Some numerical techniques and their use in the extension of T-matrix and null-field approaches to scattering

Abstract

Acoustic, electromagnetic and elastic scattering have been described by the T-matrix method of Waterman. High-frequency calculations and the description of scattering from general bounded surfaces can give rise to large sets of basis states, which in turn necessitate computation of large ill-conditioned matrices. Difficulties in handling these matrices place limitations on the T-matrix and null-field methods. A number of numerical and theoretical techniques are presented which overcome these difficulties and extend the range of applicability of these methods beyond the conventional approach.